Abstract: A shockwave generator is adapted to be coupled to an object through a liquid medium for ultrasound transmission to generate a shockwave in the object. The shockwave generator comprises a piezoelectric element having an ultrasound radiating surface, an acoustic matching layer formed on the ultrasound radiating surface of the piezoelectric element, a fluorine-resin coating layer formed on the acoustic matching layer and a bag provided in front of the ultrasound radiating surface of the piezoelectric element and holding water for ultrasound transmission, where the water is held in contact with the fluorine-resin coating layer.

Abstract: An ultrasonic probe system is disclosed, which is designed to allow connection of a DC power supply capable of applying a voltage higher than the coercive electric field of each of a plurality of piezoelectric layers thereto, and includes a polarization turn over circuit means for, when the DC power supply is driven, turning over the polarity of the DC power supply so as to direct electric fields of every two adjacent layers constituting the piezoelectric layers in substantially opposite directions or electric fields of all the layers in the same direction.

Abstract: An ultrasonic probe includes a probe head having a piezoelectric element which includes a plurality of piezoelectric layers which are laminated in the thickness direction thereof with the polarity directions of the adjacent piezoelectric layers set opposite to each other and each of which has opposite end surfaces, electrodes formed on the opposite end surfaces of the piezoelectric layers in the laminated direction, a plurality of external electrodes formed on the opposite end surfaces of the piezoelectric layers on the laminated direction, internal electrodes formed in the lamination interface of the piezoelectric layers, an acoustic matching layer having a plurality of layers and formed on one surface of the plurality of laminated piezoelectric layers, an acoustic lens disposed on the matching layer with the convex surface thereof set towards the outside, and a backing material disposed on the other surface of the piezoelectric element.

Abstract: An ultrasonic medical treatment apparatus having an piezoelectric element for generating ultrasonic energy is provided. The element is constituted by a plurality of unit piezoelectric elements of two or more different shapes. The surface areas of these unit elements are substantially equal to each other. These unit elements can be individually removed as required.

Abstract: An ultrasonic imaging apparatus includes an ultrasonic transducer for outputting an ultrasonic beam and converting the echo of the ultrasonic beam into an echo signal, a transmitter section for supplying a drive signal to the ultrasonic transducer, a receiver section for receiving the echo signal output from the ultrasonic transducer and converting the echo signal into an image signal, and a coaxial cable for coupling the ultrasonic transducer to the transmitter and receiver sections. The ultrasonic transducer is constituted by a two-layer ultrasonic transducer having an impedance smaller than an impedance of the coaxial cable.